(136108) Haumea, Hi'iaka, and Namaka

compiled by Wm. Robert Johnston
last updated 1 April 2009

Orbital elements and other data (Assumed or derived values in parenthesis, my estimates in italics and parenthesis. Source identifications in brackets, see this link for sources):

orbital data, primary (osculating elements) [JPL]:
semimajor axis a: 43.08080 AU
orbital period P: 282.77 y (=103,282 d)
eccentricity e: 0.196302
perihelion distance q: 34.62395 AU
aphelion distance Q: 51.53765 AU
inclination i: 28.224530°
argument of perihelion omega: 239.3599°
ascending node OMEGA: 122.103987°
mean anomaly M: 203.1737°
perihelion passage TP: 2132-08-25
Epoch: 18 JUN 2009
data arc: 1955-2008 (440 obs.)

orbital data, Hi'iaka:
semimajor axis a: 49,880 ± 198 km [R09a]
semimajor axis/primary radius a/Rp: (71)
orbital period P: 49.462 ± 0.083 d [R09a]
eccentricity e: 0.0513 ± 0.0078 [R09a]
inclination i: 126.356° ± 0.064° [R09a]
argument of perihelion omega: 154.1° ± 5.8° [R09a]
ascending node OMEGA: 206.766° ± 0.033° [R09a]
mean anomaly M: 152.8° ± 6.1° [R09a]

orbital data, Namaka:
semimajor axis a: 25,657 ± 91 km [R09b]
semimajor axis/primary radius a/Rp: (37)
orbital period P: 18.2783 ± 0.0076 d [R09b]
eccentricity e: 0.249 ± 0.015 [R09a]
inclination i: 113.013° ± 0.075° [R09a]
13.41° ± 0.08° (relative to Hi'iaka) [R09a]
argument of perihelion omega: 178.9° ± 2.3° [R09a]
ascending node OMEGA: 205.016° ± 0.228° [R09a]
mean anomaly M: 178.5° ± 1.7° [R09a]

other data, primary:
diameter: (1400 km) [R05b]
triaxial dimensions: 1960 km x 1518 km x 996 km ? [R05b]
absolute magnitude H: 0.44 [R05a]
rotation period: 3.9154 ± 0.0002 h [R05b]
amplitude delta M: 0.30 ± 0.02 [L08a]
color index B-V: (0.626 ± 0.025) [R05b]
color index V-R: (0.343 ± 0.020) [R05b]
color index B-R: 0.972 ± 0.014 [L08a]
color index V-I: (0.683 ± 0.020) [R05b]
color index R-J: 0.885 ± 0.012 [L08a]
color index J-H: -0.057 ± 0.016 [L08a]
color index F110W-F160W: -1.208 ± 0.004 [F09a]
slope parameter G: (0.15) [a]
geometric albedo: 0.70 ± 0.10 [R05b]
mass: (4.006±0.040)x1021 kg [B05a]
density: 2,600 to 3,340 kg/m3 [R05b]
type: ?

other data, Hi'iaka:
diameter: ~320 km [R09a]
diameter ratio Ds/Dp: (~0.23)
component magnitude difference: (2.98 ± 0.03) [L08a]
rotation period: ?
color index J-H: -0.399 ± 0.034 [L08a]
color index F110W-F160W: -1.48 ± 0.06 [F09a]
geometric albedo: (0.80±0.07) [R09a]
mass ratio: 0.00451 ± 0.00030 [R09a]
mass: (1.79±0.11)x1019 kg [R09a]
density: 1±0.5 g/cm3 [a]

other data, Namaka:
diameter: ~160 km [R09a]
diameter ratio Ds/Dp: (~0.11)
component magnitude difference: (4.6)
rotation period: ?
amplitude delta M: 0.3? [F09a]
color index F110W-F160W: -1.4 ± 0.2 [F09a]
geometric albedo: (0.8±0.2) [R09a]
mass ratio: 0.00051 ± 0.00036 [R09a]
mass: (1.79±1.48)x1018 kg [R09a]
density: 1±0.5 g/cm3 [a]

--(136108) Haumea--discovery and notes:

Primary discovered by J. L. Ortiz, F. J. Aceituno, P. Santos-Sanz, and J. Nomen in 2005 from images taken on 7 March 2003 from Sierra Nevada. Subsequently linked to prediscovery observations from 1955. Other designations K40506A. Informally designated "Santa" by the Brown et al. team, which observed the object independently in 2004-2005. Permanent number assigned 7 September 2006. Name, assigned 17 September 2008, was that proposed by Brown et al.; Ortiz et al. had reportedly proposed the name Ataecina.

Hi'iaka discovered 26 January 2005 by the Keck Observatory adaptive optics telescope by A. Bouchez, M. Brown, R. Campbell, J. Chin, M. van Dam, S. Hartman, E. Johansson, R. Lafon, D. Le Mignant, P. Stomski, D. Summers, P. Wizinowich, C. Trujillo, and D. Rabinowitz. Name assigned 17 September 2008.

Namaka discovered 30 June 2005 by M. E. Brown, M. A. van Dam, A. H. Bouchez, D. Le Mignant, R. D. Campbell, J. C. Y. Chin, A. Conrad, S. K. Hartman, E. M. Johansson, R. E. Lafon, D. L. Rabinowitz, P. J. Stomski, Jr., D. M. Summers, C. A. Trujillo, and P. L. Wizinowich. Announced 7 November 2005. Name assigned 17 September 2008.

See more information and links at Asteroid/Comet Connection Catchall Catalog page

--Links, more technical:

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--Links to ADS abstracts:


© 2005-2008, 2009 by Wm. Robert Johnston.
Last modified 1 April 2009.
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